<!DOCTYPE html>
<html>
<head>
<style>
#b::first-letter { }
#c::first-line { }
</style>
</head>
<body>
This page should not crash Mozilla
<div id="c">
  <table>
    <div id="b" style="display:table-header-group;">
      <q>
        text
        <div style="position:fixed;">
          <q>y</q>
        </div>
      </q>  
    </div>
    <span style="display: table;"></span>
</div>

</body>
</html>
